CheckDigits::M11_001(3User Contributed Perl DocumentatiCheckDigits::M11_001(3)NAME
CheckDigits::M11_001 - compute check digits for ISBN, ISSN, VAT RN
(PT), HKID (HK), Wagon number (BR), NHS (GB), VAT (SL)
SYNOPSIS
use Algorithm::CheckDigits;
$isbn = CheckDigits('isbn');
if ($isbn->is_valid('3-88229-192-3')) {
# do something
}
$cn = $isbn->complete('3-88229-192-');
# $cn = '3-88229-192-3'
$cd = $isbn->checkdigit('3-88229-192-3');
# $cd = '3'
$bn = $isbn->basenumber('3-88229-192-3');
# $bn = '3-88229-192-'
DESCRIPTION
ALGORITHM
1. The sequence of digits is processed right to left. Every digit is
multiplied with their position in the sequence (i.e. the digit
left to the check digit has the weight 2 then 3 etc.).
With a Hongkong ID (hkid) the leftmost char is replaced with its
position in the alphabet and then multiplied with 8 (its weight).
2. The sum of all products is computed.
3. The sum of step 2 is taken modulo 11.
4. The checkdigit is the difference of the sum from step 3 to eleven
under the following conditions:
isbn,issn
If the difference is 10, the check digit is 'X'.
If the difference is 11, the check digit is 0.
ustid_pt
If the difference is greater then 9, the check digit is
'0'.
hkid If the difference is 10, the check digit is 'A'.
If the difference is 11, the check digit is 0.
wagonnr_br
If the difference is 10, the check digit is 0.
If the difference is 11, the check digit is 1.
nhs_gb If the difference is 10, the number would not be taken.
If the difference is 11, the check digit is 0.
vat_sl This is a little bit unclear, don't trust on the method for
this type.
METHODS
is_valid($number)
Returns true only if $number consists solely of numbers and the
last digit is a valid check digit according to the algorithm given
above.
Returns false otherwise,
complete($number)
The check digit for $number is computed and concatenated to the end
of $number.
Returns the complete number with check digit or '' if $number does
not consist solely of digits and spaces.
basenumber($number)
Returns the basenumber of $number if $number has a valid check
digit.
Return '' otherwise.
checkdigit($number)
Returns the checkdigit of $number if $number has a valid check
digit.
Return '' otherwise.
EXPORT
None by default.
AUTHOR
Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>
SEE ALSO
perl, CheckDigits, www.pruefziffernberechnung.de.
perl v5.14.1 2009-11-20 CheckDigits::M11_001(3)
